The procedural safeguards that are implied in that question are dealt with in the legislation and in the legal system.
Officials, including the Minister of Health, who exercise powers granted to them in a statute enacted by Parliament--and in this case it would be Bill C-36--are compelled by law to act reasonably. That is to say, they must make decisions with impartiality and fairness. Fairness requires them to act reasonably and to afford procedural protection to the person who is affected by their decision. Officials, including the minister, cannot act in an arbitrary manner. And as I've mentioned, under Bill C-36 this protection is afforded to a person requesting a review of an order.
I would like to add that the legal requirements--the principles of administrative law--do not require that every appeal or review mechanism be structured like courts or quasi-judicial tribunals in order to ensure procedural fairness. And while the minister designates the review officer, once the officer is designated he or she makes the decision and cannot be dictated to, although they can take into account guidelines and departmental policies in making a decision.